1. Technical Field
The present disclosure generally relates to correction methods for robot manipulators, and particularly to a vision correction method for tool center point of a robot manipulator.
2. Description of Related Art
Robot manipulators are used in various industrial fields to fulfill the task requirements for product assembling, welding and other tasks automatically. A robot manipulator of related art may be equipped with a tool, such as a gripper, a cutting device, a glue dispenser or a fixture mounted to a distal end thereof. The tool has a specific defined point, called the Tool Center Point (TCP), that is commanded to move to various positions in the workspace when a robot manipulator performs a task. In use, the positional accuracy of the robot manipulator directly depends on knowing the precise position of the TCP relative to the robot manipulator's distal end. Since the tool may have been mounted to the distal end of the robot manipulator manually, an alignment error may arise between the tool and the robot manipulator, causing the TCP to deviate from its expected position. Thus, to ensure tasks are performed with high positional accuracy, the position of the TCP relative to the robot manipulator's distal end must be calibrated to correct for tool misalignment after mounting or collision. Presently, the standard method for calibrating the TCP position requires an operator to visually guide the TCP to a specific point in the workspace with the tool at a minium of four different orientations. This is a time-consuming and inconvenient manual process, and the correction precision is not guaranteed. Automated calibration systems that use light beams to determine the TCP position are known in the art. However, these automated systems are not widely used due to their high cost, laborious setup process, or long calibration process time.
Therefore, there is room for improvement within the art.